The average United States commuter spends approximately 42 hours in traffic per year. In 2016, this averaged to about $1,400 per driver in gasoline expenses. These amounts may vary widely depending on the city, with more heavily populated cities commuters spending even more time and money due to frequent stop-and-go traffic. For example, commuters in Miami, Fla. averaged 65 hours in traffic and a cost of about $1,800 per driver while commuters in Los Angeles, Calif. averaged 104 hours in traffic and about $2,400 per driver. Though traffic accidents play into the transit times in larger cities, in smaller cities and towns traffic controls typically dictate the flow of traffic.
Traditionally, traffic control signals incorporated different types of technologies that may detect cars, such as timers, lasers, rubber hoses filled with air, and an inductive loop. With such a wide range of technology available to regulate traffic, some lights do not have any sort of traffic detection. In large cities, traffic lights may operate on timers. In suburbs and country roads, traffic detectors may be common. Detectors may trigger when a car arrives at an intersection, when too many cars are at an intersection, or when cars have entered a turn lane, so that the detector may activate the arrow light.
The most common form of traffic control is an inductive loop. The inductive loop is a coil of wire embedded in a road's surface. Vehicle presence is detected through electromagnetic induction, where a vehicle triggers the inductive loop to signal the traffic controller that there is traffic waiting at the intersection. Typically, the inductive loop is triggered just before the stop bar in a traffic lane, which is the thick white line painted on the pavement that signals to motorists where they should stop so that the traffic controller may detect effectively.
Traffic sensors associated with preemption systems are programmed to only detect certain infra-red signals from emergency vehicles and cannot be deceived by activating a green light for passenger vehicles.
Currently, most traffic lights are poorly timed and inefficient because transportation agencies do not have the personnel or financial resources to update these systems or to implement newer traffic technologies that could reduce delay at intersections. Without experienced personnel or money for updates and improvements, cities and rural areas are unable to improve the efficiency of their traffic control systems and motorists, and by default, people waste time, fuel, and, ultimately, money, due to traffic mismanagement.